I’m working on a Country Club lot for all my fancy pants sims currently. I’ve also been working on a few faith based lots. A Catherdral, a Mosque and a Far East inspired Temple.
I’ve found that my most creative lots are sparked from clubs I create. My It Girl’s club inspired a cafe/clothing store hybrid. My sports teams inspired me to build a school. I have restaurants catered to specific food types and themed accordingly; a Mexican cantina, an Italian pizzeria, a seafood place, a breakfast and burgers style diner, a sushi/Asian fusion place, a vegetarian eatery, a Chuck E. Cheese style kid friendly restaurant, and a black tie upscale restaurant that serves primarily experimental food.
I only keep one gym, one museum, and one library for all the neighborhoods so that they always feel lively and to free up space for other lots.